Search results for "Brain Injuries"
showing 10 items of 139 documents
Applying univariate vs. multivariate statistics to investigate therapeutic efficacy in (pre)clinical trials: A Monte Carlo simulation study on the ex…
2020
BackgroundSmall sample sizes combined with multiple correlated endpoints pose a major challenge in the statistical analysis of preclinical neurotrauma studies. The standard approach of applying univariate tests on individual response variables has the advantage of simplicity of interpretation, but it fails to account for the covariance/correlation in the data. In contrast, multivariate statistical techniques might more adequately capture the multi-dimensional pathophysiological pattern of neurotrauma and therefore provide increased sensitivity to detect treatment effects.ResultsWe systematically evaluated the performance of univariate ANOVA, Welch's ANOVA and linear mixed effects models ver…
Ketamine in acute phase of severe traumatic brain injury “an old drug for new uses?”
2021
AbstractMaintaining an adequate level of sedation and analgesia plays a key role in the management of traumatic brain injury (TBI). To date, it is unclear which drug or combination of drugs is most effective in achieving these goals. Ketamine is an agent with attractive pharmacological and pharmacokinetics characteristics. Current evidence shows that ketamine does not increase and may instead decrease intracranial pressure, and its safety profile makes it a reliable tool in the prehospital environment. In this point of view, we discuss different aspects of the use of ketamine in the acute phase of TBI, with its potential benefits and pitfalls.
Intracranial measurement of current densities induced by transcranial magnetic stimulation in the human brain
2003
Transcranial magnetic stimulation (TMS) is a non-invasive technique that uses the principle of electromagnetic induction to generate currents in the brain via pulsed magnetic fields. The magnitude of such induced currents is unknown. In this study we measured the TMS induced current densities in a patient with implanted depth electrodes for epilepsy monitoring. A maximum current density of 12 microA/cm2 was recorded at a depth of 1 cm from scalp surface with the optimum stimulation orientation used in the experiment and an intensity of 7% of the maximal stimulator output. During TMS we recorded relative current variations under different stimulating coil orientations and at different points…
Nitric Oxide/Cyclic Guanosine Monophosphate Signaling via Guanylyl Cyclase Isoform 1 Mediates Early Changes in Synaptic Transmission and Brain Edema …
2021
Traumatic brain injury (TBI) often induces structural damage, disruption of the blood-brain barrier (BBB), neurodegeneration, and dysfunctions of surviving neuronal networks. Nitric oxide (NO) signaling has been suggested to affect brain functions after TBI. The NO exhibits most of its biological effects by activation of the primary targets-guanylyl cyclases (NO-GCs), which exists in two isoforms (NO-GC1 and NO-GC2), and the subsequently produced cyclic guanosine monophosphate (cGMP). However, the specific function of the NO-NO-GCs-cGMP pathway in the context of brain injury is not fully understood. To investigate the specific role of the isoform NO-GC1 early after brain injuries, we perfor…
Validation of brain extracellular glycerol as an indicator of cellular membrane damage due to free radical activity after traumatic brain injury.
2008
Following severe traumatic brain injury (TBI), increasing oxygen delivery to the brain has been advocated as a useful strategy to reverse mitochondrial dysfunction and improve neurological outcome. However, this might also promote overproduction of free radicals, responsible for lipid peroxidation and hence brain cell damage. Therefore, a method for monitoring this potential adverse effect in humans is desirable. Glycerol, an end product of phospholipid breakdown, easily detectable in the human brain by means of microdialysis, might represent a reliable indicator of free radical-induced cell membrane damage. Brain microdialysates were collected from 24 adult male Sprague-Dawley rats over a …
Correction to: Depletion of regulatory T cells increases T cell brain infiltration, reactive astrogliosis, and interferon-γ gene expression in acute …
2019
Traumatic brain injury (TBI) is a major cause of death and disability. T cells were shown to infiltrate the brain during the first days after injury and to exacerbate tissue damage. The objective of this study was to investigate the hitherto unresolved role of immunosuppressive, regulatory T cells (Tregs) in experimental TBI."Depletion of regulatory T cell" (DEREG) and wild type (WT) C57Bl/6 mice, treated with diphtheria toxin (DTx) to deplete Tregs or to serve as control, were subjected to the controlled cortical impact (CCI) model of TBI. Neurological and motor deficits were examined until 5 days post-injury (dpi). At the 5 dpi endpoint, (immuno-) histological, protein, and gene expressio…
Pathophysiology of traumatic brain injury.
2007
The knowledge of the pathophysiology after traumatic head injury is necessary for adequate and patient-oriented treatment. As the primary insult, which represents the direct mechanical damage, cannot be therapeutically influenced, target of the treatment is the limitation of the secondary damage (delayed non-mechanical damage). It is influenced by changes in cerebral blood flow (hypo- and hyperperfusion), impairment of cerebrovascular autoregulation, cerebral metabolic dysfunction and inadequate cerebral oxygenation. Furthermore, excitotoxic cell damage and inflammation may lead to apoptotic and necrotic cell death. Understanding the multidimensional cascade of secondary brain injury offers…
Prevention and treatment of intracranial hypertension
2007
Intracranial pressure (ICP) is the pressure exerted by cranial contents on the dural envelope. It comprises the partial pressures of brain, blood and cerebrospinal fluid (CSF). Normal intracranial pressure is somewhere below 10 mmHg; it may increase as a result of traumatic brain injury, stroke, neoplasm, Reye's syndrome, hepatic coma, or other pathologies. When ICP increases above 20 mmHg it may damage neurons and jeopardize cerebral perfusion. If such a condition persists, treatment is indicated. Control of ICP requires measurement, which can only be performed invasively. Standard techniques include direct ventricular manometry or measurement in the parenchyma with electronic or fiberopti…
Comparison of speed-vacuum method and heat-drying method to measure brain water content of small brain samples
2016
Abstract Background A reliable measurement of brain water content (wet-to-dry ratio) is an important prerequisite for conducting research on mechanisms of brain edema formation. The conventionally used oven-drying method suffers from several limitations, especially in small samples. A technically demanding and time-consuming alternative is freeze-drying. New method Centrifugal vacuum concentrators (e.g. SpeedVac/speed-vacuum drying) are a combination of vacuum-drying and centrifugation, used to reduce the boiling temperature. These concentrators have the key advantages of improving the freeze-drying speed and maintaining the integrity of dried samples, thus, allowing e.g. DNA analyses. In t…
Normalization with Corresponding Naïve Tissue Minimizes Bias Caused by Commercial Reverse Transcription Kits on Quantitative Real-Time PCR Results
2016
Real-time reverse transcription polymerase chain reaction (PCR) is the gold standard for expression analysis. Designed to improve reproducibility and sensitivity, commercial kits are commonly used for the critical step of cDNA synthesis. The present study was designed to determine the impact of these kits. mRNA from mouse brains were pooled to create serial dilutions ranging from 0.0625 μg to 2 μg, which were transcribed into cDNA using four different commercial reverse-transcription kits. Next, we transcribed mRNA from brain tissue after acute brain injury and naïve mice into cDNA for qPCR. Depending on tested genes, some kits failed to show linear results in dilution series and revealed s…